The invention relates to a method and apparatus for moving a piston. More particularly, but not by way of limitation, the invention relates to a method and apparatus for urging a piston in order to generate a force relative to a housing by applying the venturi principle to a down hole apparatus.
In the development of oil and gas fields, well bores are drilled through subterranean reservoirs. Ultimately, a well will be completed to a hydrocarbon bearing reservoir, as will be understood by those of ordinary skill in the art. Afterwards, the hydrocarbon bearing reservoir is produced, and the hydrocarbons are ultimately sold.
The well bores are generally of small diameter and many times are highly deviated. The forces necessary to drill these well bores are significant. Many of the tools developed over the years depend on rotation of a tool string, gravitational forces, hydraulic forces and/or pneumatic forces. Moreover, during the completion phase, in order to accomplish the necessary procedures, the operator will find it necessary to employ the use of work strings that can transmit force in order to accomplish the completion and/or remedial work involved.
Sometimes, the force necessary to perform these operations is supplied with the work string weight. Other times, the force is supplied through rotation of the work string. Still yet other times the force is supplied through hydraulic means.
In those cases wherein the force required can not be generated due to lack of weight, rotation is not possible, excessive well bore angle, or the small diameter well bore limits tool function, operators have attempted various designs. For instance, down hole drilling motors have been developed that rotate a drill bit through fluid circulation. However, forces necessary to place the appropriate weight on bit may not be present due to the deviated nature of the well. Certainly, other factors may be present due to the specific circumstances of individual well bores that limit the application of force, and thus, limit the operators effectiveness to drill, complete and produce the well.
Therefore, there is a need for a method and apparatus that will allow for the application of a force regardless of the hole deviation, weight of the tool string, and/or lack of rotation.